286 



W. L. WATERHOUSE. 



obtained under artificial conditions, but it is by no means 

 impossible for the requisite conditions for infection to occur 

 in Nature. 



A f urtlier reason for urging that the barberry should be 

 restricted is that American fodder is sometimes imported 

 into Australia. If teleutospores of Puccinia graminis 

 should be present on it and the sporidia find their way on 

 to a barberry, the resultant infection might lead to the 

 spread in Australia of a virulent American biologic form 

 of the rust. 



The greatest danger is present in the cool districts. It 

 is difficult to understand why the place of the barberry 

 should not be filled by one or other of our many harmless 

 native shrubs. If this be not desired, then at least the 

 distribution of barberries should be restricted to Berberis 

 Thunbergii, which is immune to the rust. 



Summary. 



1. Under set conditions for inoculation, two plants of 

 Berberis vulgaris were proved to be susceptible to sporidia 

 of Puccinia graminis obtained from rusty British wheat. 



2. Inoculations of the same plants under similar con- 

 ditions with viable teleutospores obtained from Glen Innes, 

 New South Wales, gave numerous infections. 



3. Spermagonia and aecidia were produced, and from the 

 latter aecidiospores were used to reinfect wheat. 



4. The aecidial stage produced by the Australian rust 

 shows no marked differences to the British rust. 



5. The distribution of barberry plants should be discon- 

 tinued. 



Literature Cited. 



(1) 1918— Stakman, E. C. "The Black Stem Rust and the 

 Barberry." Yearbook of U. S. Department of 

 Agriculture, p. 4. 



